First time desining a sail

I was wondering if any one could suggest a good design for a sail/rigid wing or even a drawing of a good design. I'm doing a design project at uni and have to design a sail for a landyacht. I was struggling to decide firstly if i should use a rigid wing or a sail, I know the basics to each but not sure which would be suitable for a 100meter race. Or if I'm better making the sail or buying a cheap one? Also I was wondering if someone could explain the aspect ratio? Again I have read notes on it but still a little unclear.

The landyacht does need to have a driving mechanism as part of the task too (for extra info). The height restriction means the total height of the land yacht can only be 4m but the boom has to clear the pilots head, so we reckon we will only manage around 2.6m max for the mast length (the driving mechaniusm has to be covered so we placed it under where the seat and obviously had to make the structure safe by adding supports)

The mast is going to be around 2.6m high, due to a height restriction, and the boom length will be 1.8m. The mast can be made out of
Cold Formed Square Hollow Sections Grade S235
the diameter can vary from 20*20*2mm to 50*50*3mm, I have done some calculations on solidworks and 30*30*3mm should be suitable.
wind speed on the day can vary a lot but an average value would be 7.5m/s up to about 13m/s maximum

The pilot weight and chasis is about 100kg maybe 110kg and after solidwork calculations, the chasis should be easily strong enough to support the pilot.

thanks for taking the time to reply! This is the first time I have ever done something involving a land yacht

the sail calculations i have done would be creating a drag force of 623m/s in the max wind conditions of 13m/s

I have calculated the aspect ratio as 2.297 but wondering what the optimum ratio would be?
the surface will be on salt

Can you tell us more about this "drive mechanism" - actually - can you fill us in with a decent description of your design requirements?

With better info we may be able to throw a few ideas around for you to think about.

We all love a challenge - and get a buzz seeing students constructing, sailing and problem solving.

We regularly have school and university students asking for help with projects, and don't mind giving you pointers and helping out,

However a few have almost expected us to do all the hard work for them - leaving them to pick up the prize at the end of the competition.

So - expect hints, and pushes in certain directions, and we need to see drawings and pictures!

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I might be jumping the gun with this [not enough info about your design requirements]

This "drive mechanism" thingo - if you can scrounge the hub from an electric bike, you might be able to lace it into the centre of the front wheel.

Then you could have your pilot almost prone in the seat - lowering the C.O.G, giving much less drag than an upright pilot, and your boom can be much lower- giving more sail area.
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Also - where is this salt you will be sailing on?

stephen

Totally agree "landyacht" with the mast height restrictions they are going to need LOTS of square meters of sail (that can only go out sideways) to launch you 100mtrs.

13m/s is 25knots, so I would aim at being less elegant, with a simple 5.5m2 area sail and blitz the high tech field. Who are just getting their wing to work at the 100mtr mark.

It wont need to be very well mannered for just 100mtrs.

We need some photos of race day. That's a given!!!!

A 100 metre dash in a more or less downwind direction A spinnaker may well be the answer